Neutralization of acid and production of carbonate-containing compositions

Abstract

Provided are methods and systems for neutralizing acidic solution. In such methods, an acidic solution may be generated and methods of raising the pH of the acidic solution are provided that may utilize rocks or mineral. Methods for processing rocks and minerals for digestion by an acidic solution are described. Digestion products of rocks and minerals are provided.

1 - 72 . (canceled) 
     
     
         73 . A method comprising:
 a. an electrochemical reaction to generate a first solution in a first compartment and a second solution in a second compartment of an electrochemical system wherein the first solution is alkaline and the second solution is acidic, wherein the acidic solution has a pH that is less than 1.3;   b. sequestering carbon dioxide from a gas comprising carbon dioxide; wherein the sequestering the carbon dioxide comprises contacting the gas with a first portion of the first solution;   c. digesting an acid neutralizing material with the second solution to produce a digestion product comprising a third solution, wherein the pH of the third solution is higher than pH of the second solution.   
     
     
         74 . The method of  claim 73  wherein the digestion product comprises calcium. 
     
     
         75 . The method of  claim 73  wherein the pH of the third solution is at least 0.5 pH points greater than the pH of the second solution. 
     
     
         76 . The method of  claim 73  wherein the digestion product comprises silicate. 
     
     
         77 . The method of  claim 73  wherein a portion of the digestion product is contacted with the sequestered carbon dioxide. 
     
     
         78 . The method of  claim 73  wherein the electrochemical reaction is configured to not produce chlorine gas. 
     
     
         79 . A method comprising:
 a. generating a first solution and a second solution in an electrochemical reaction;   wherein the first solution is alkaline and the second solution is acidic and wherein the electrochemical reaction is configured to not produce chlorine gas   b. digesting an acid neutralizing material with the second solution to form a slurry comprising a third solution, wherein the pH of the third solution is greater than the second solution by at least 0.5 pH units.   
     
     
         80 . The method of  claim 79  wherein the electrochemical reaction comprises
 i. separating an anode electrolyte in contact with a gas diffusion anode from a cathode electrolyte in contact with a cathode using an ion exchange membrane in an electrochemical system; 
 ii. applying a voltage across the gas diffusion anode and cathode; 
 iii. directing hydrogen gas to the gas diffusion anode using hydrogen gas produced at the cathode; 
 iv. oxidizing hydrogen gas to protons at the anode without producing a gas at the anode; 
 v. migrating protons from the anode into the anode electrolyte to produce the second solution in the anode electrolyte to avoid the production of a gas. 
 
     
     
         81 . The method of  claim 79  further comprising:
 c. sequestering carbon dioxide from a gas comprising carbon dioxide; wherein sequestering the carbon dioxide comprises contacting the gas with the first solution. 
 
     
     
         82 . The method of  claim 79  wherein the second solution is between 40 and 84° C. when contacting the acid neutralizing material. 
     
     
         83 . The method of  claim 79  wherein the third solution comprises calcium. 
     
     
         84 . The method of  claim 79  wherein the second solution comprises an acid selected from hydrochloric acid, sulfuric acid, acetic acid, hydrofluoric acid, boric acid and nitric acid. 
     
     
         85 . The method of  claim 73  wherein the second solution comprises an acid selected from hydrochloric acid, sulfuric acid, acetic acid, hydrofluoric acid, boric acid and nitric acid. 
     
     
         86 . The method of  claim 79  wherein the second solution comprises hydrochloric acid. 
     
     
         87 . The method of  claim 79  wherein the second solution is between 10 and 36 wt % acid. 
     
     
         88 . The method of  claim 79  wherein the pH of second solution is between −1 and 1. 
     
     
         89 . The method of  claim 73  wherein the pH of second solution is between −1 and 1. 
     
     
         90 . The method of  claim 79  wherein the acid neutralizing material comprises less than 1 wt % carbonate. 
     
     
         91 . The method of  claim 73  wherein the acid neutralizing material comprises an alkaline earth metal silicate or an alkaline earth phorsphorite. 
     
     
         92 . The method of  claim 91  further comprising contacting the alkaline earth metal with the sequestered carbon dioxide to precipitate a carbonate containing compound. 
     
     
         93 . The method  claim 79  wherein the acid neutralizing material comprises silicates or phosphorus. 
     
     
         94 . The method of  claim 93  wherein digesting the acid neutralizing material releases silicates into the third solution. 
     
     
         95 . The method of  claim 94  further comprising combining the sequestered carbon dioxide and the silicates to produce a building material. 
     
     
         96 . The method of  claim 73  wherein the acid neutralizing material comprises mafic rock. 
     
     
         97 . The method of  claim 96  wherein the mafic rock comprises basalt. 
     
     
         98 . The method of  claim 73  wherein the acid neutralizing material comprises ultramafic rock. 
     
     
         99 . The method of  claim 73  wherein the acid neutralizing material comprises felsic rock. 
     
     
         100 . The method of  claim 73  wherein the acid neutralizing material is anorthite and wherein contacting anorthite and the acidic solution forms kaolinite and a divalent cation. 
     
     
         101 . The method of  claim 100  further comprising converting the kaolinite to metakaolin. 
     
     
         102 . The method of  claims 73  further comprising contacting the third acidic solution with a second portion of the first solution. 
     
     
         103 . The method of  claim 102  wherein the contacting with a second portion of the first solution generates a neutralized solution. 
     
     
         104 . The method of  claim 103  further comprising disposing of the neutralized solution an underground location. 
     
     
         105 . The method of  claim 104  further comprising utilizing a portion of the neutralized solution in the electrochemical reaction. 
     
     
         106 . The reaction of  claims 73  wherein the electrochemical reaction proceeds after a voltage of less than 2 volts is applied. 
     
     
         107 . The reaction of  claim 73  wherein the electrochemical reaction is configured to avoid production of chlorine gas. 
     
     
         108 . A system for sequestering carbon dioxide comprising:
 a. an electrochemical system suitable for generating an first solution in a first compartment and a second solution in a second compartment, wherein the second compartment is suitable for containing a solution that has a pH that is less than 1.3;   b. a first reaction vessel operably connected to a source of waste gas and the electrochemical system connected to an absorber suitable for contacting a gas comprising carbon dioxide with the first solution to sequester carbon dioxide; and   c. a second reaction vessel operably connected to the electrochemical system and a source of an acid neutralizing material suitable to contact the second solution comprising a pH of less that 1.3 with the acid neutralizing material wherein the contact is sufficient to form a third solution that has a higher pH than the second solution.   
     
     
         109 . The system of  claim 108  wherein the acid neutralizing material comprises a divalent cation and wherein the third solution comprises divalent cation released from the acid neutralizing material; and
 a. further comprising a third reaction vessel operably connected to the first reaction vessel and the second reaction vessel suitable for contacting the third solution to the sequestered carbon dioxide wherein the contact is sufficient to generate a carbonate precipitate. 
 
     
     
         110 . The system according to  claim 108  wherein the electrochemical system is configured to prevent the release of chlorine gas. 
     
     
         111 . The system according to  claim 108  wherein the electrochemical system is configured to the produce the acidic solution composition at a voltage of 2.0 volts or less. 
     
     
         112 . The system according to  claim 108  wherein reaction vessel is suitable for promoting the release of an alkaline earth metal from the acid neutralizing material into the third solution.